Hi!
First of all, you cannot publish three WSDL at the same endpoint address.
An option is to merge the WSDLs by creating a PortType ABC that contains all the operations from the ABC PortType in the three different WSDLs.
Additionally, you do not implement a service in the manner you have done. Try searching the internet for a tutorial on wsdl-first development for the development environment you use.
Please do not hesitate to ask if there are additional questions!
Best wishes!